Please see the above image.
1) At the top of the lens after the hood is the
focusing ring. That ring allows you to manually focus the lens.
2) Below that ring is what I believe you are referring to - that is the
focusing scale. Those numbers in ft/meter tell you the distance at which it focuses.
3) The numbers below the focusing scale is the
hyperfocal range and is used to do zone focusing (which you may learn in your class).
4) The last ring with the green A is the
aperture ring and allows you to manually set the aperture on the lens. If your lens has that aperture ring, you will be able to use practically any Pentax film camera. If you do not have that ring, you need a more advanced Pentax film camera that can electronically control the aperture.
Above, an example of a Pentax DA lens without #2, 3, and 4.
Pentax P30T - Manual Focus Film SLRs - Pentax Camera Reviews and Specifications - An example of a Pentax film camera with manual focusing and capability to control aperture.